This invention relates to multidisc type brakes or clutches and particularly to the torque transmitting drive lugs fastened to the radially inner surface of the rim of a wheel for engagement with brake rotors. Heretofore, such torque transmitting drive lugs have been mounted on the radially inner surface of the wheel rim and have been in the form of individual members extending axially along the radially inner surface of the wheel rim. These drive lugs have been attached to the radially inner surface of the wheel rim at its flange by a threaded fastener and at the opposite end by insertion of such end of the drive lug into an aperture formed in the web of the wheel adjacent to the rim. Problems with drive lugs of the type just described have included excessive deflection in operation due to high bending moments induced upon actuation of the brake. To overcome such high bending moments, it has been necessary to use relatively heavy drive lugs to provide the necessary strength and resistance to deflection induced by torque.
The following patents are exemplary of previous efforts in this field.
U.S. Pat. No. 4,131,321 to J. A. Hall discloses a torque lug drive system in which the drive lugs are mounted in a drum extending axially outwardly of the wheel. Annular ribs on the inside of the drum provide reinforcement of the drum and protection for the lugs. Additional axially extending ribs inside the drum provide further reinforcement of the drum which may be thin and lightweight because of the reinforcement.
U.S. Pat. No. 4,585,096 to L. D. Bok discloses a split disc for a brake or clutch. FIG. 1 illustrates a method of attachment of drive lugs for the rotor discs in which the inboard end of a drive lug is received in a bore in the wheel web and the outboard end of the drive lug is fastened by a bolt to the wheel rim.
U.S. Pat. No. 4,018,482 discloses a disc-type brake or clutch having torque transmitting members fastened to the wheel for engagement with rotors of the brake or clutch. The rim construction is provided with integral torque transmitting lugs, each of which is contoured to lower the maximum tensile stresses in the lugs and rim below the desired maximum stress level.
While many different approaches to provision of torque transmitting members fastened to or integral with a wheel rim have been proposed, there remains a desire to increase the maximum load which can be carried while minimizing the weight of the torque transmitting members and their attachment to the wheel rim.